Power-transmission system



J. SCH URCH.

POWER TRANSMISSION SYSTEM. APPLICATION FILED 1AN.12,1916` kmr-neg,

I. SCHURCH. POWER TRANSMISSION SYSTEM.

Patented Aug. 24, 1920.

APPLICATION FILED JAN. I2, ISIS.

J. SCHURCH.

POWER TRANSMISSION SYSTEM. APPLICATION FILED IAN. I2, 1916.

Patented Aug. 24, 1920.

l0 SHEETS-SHEET 3.

I. SCHURCH. POWER' TRANSMISSION SYSTEM.

APPLICATION FILED IAN. l2, I9I6. 1,350,424. Patented Aug. 24, 1920.

I0 SHEETS-SHEET 4. /\Ae2z fw 6 d f C Z/ Jl'E/(` 54 f 6 77 L. 14 75 /713 J. SCHURCH.

POWER TRANSMISSION SYSTEM. APPLICATION F|LED 1AN.12,1916.

Patented Aug. 24, 1920.

l0 SHEETS-SHEET 5.

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J. SCHURCH.

POWER TRANSMISSION SYSTEM.

APPLICATION FILED IAN. I2. I9I6.

1,350,424. Patented Aug. 24, 1920.

l0 SHEETS-SHEEY 6, @la

222. 'l k Z 6 f5 .f L v O J4 Zr/ 16' 27]@66566/ y Inder@ r1 @Harney/M J. SCHURCH.

POWER TRANSMISSION SYSTEM. APPLICATION FILED IAN. I2, I9Io.

l 3 5 O, 424 Patented Aug. 24, 1920.

I0 SHEETS*SHEET 7.

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APPLICATION FILED IAN. I2. 1916. 1 3 50, 424 Patented Aug. 24, 1920.

l0 SHEETS-SHEET 8,

J. SCHURCH. POWER TRANSMISSION SYSTEM.

4 APPLICATION EILED J.AN.12.1916. 4 1,350,424.. Patented Aug. 24, 1920.

I0 SHEETS-SHEET 9.

177/ Se@ Ewa/2257".' fQ/fan' l Jao @cham/LI J. SCHURCH.

POWER TRANSMISSION SYSTEM. APPLICATION, FILED JAN.12. 1916.

l 350,424. Patented Aug. 24, 1920.

aaemeaaaacm UNITED 'STATES PATENT OFFICE.

JACOB sommen, or .HOLTVILLE, CALIFORNIA, As'sIGNOIz. r.ro IMPERIAL nLEc'rnrC COMPANY, or IioLrvILLii, CALIFORNIA, A OonPoaArroN or cAmronNiA.

POWER-TRANSMISSION SYSTEM.`

Specification of Letters Patent.

Patented Aug-24, i920.

Application mea January 12, i916. serial No. 71.648.

In general, an object of the invention is to provide for maximum flexibility' of control of the speedof the driven member.

Another object is to eifect in some instances reversal of the driven member without using current from anfexternal source.v

Another object is to efect in another instance 'reversal of the driven member by using current from an external source.

Another object is to make provision in another instance forI driving bothfront and rear axles.l v

Another object is to effect speed regular tion without loss of power/or vloweringthe efficiency.

vAnother object is to maximize thepeffective torque.

Another object is to rmake provision for E obtaining higher rotative speed of the driven member than the rotative speed of the shaft of the primemover.-

l. Another'ob]ect l1s to make provisiony Afor obtaining higher rotative speed and power.

of the driven member than the rotative speed and power of the shaft of the prime mover.

Another object is to maximize the brakingl effect.

Another object is to elect the 'foregoing by a constructionof minimum 4weight and occupying minimums ace.'

Other objects and avantages may be disclosed hereinafter.- The accompanying drawings illustrate the invention: l y

Figure 1 is a plan view. of the invention embodied in a front and rear drive'vehicle one ofthe front wheels being in section and portions of the vehicle frame.- axle ous'- sp'eed, and when t ings and othenf-ront wheell being broken .away and the electrical transmission device being in mid-section..

Fig. 2 is a fragmental sectional elevation' tire pistons and portions of twowother pistons being shown'in elevation.

Fig. 3 is a transverse sectional elevation on line Jindicated by @a3-w3, Fig. 2.

Fi 4 is a plan 'view partly in section of a di erent form of the invention embodied in a rear drivev vehicle, the wheels being omitted and portions of the Aframe being broken away to contract the view. f

Fig. 5 is .an end elevation from line indi-` cated by w-w, Fig. 4.

lFig' 's av diagram bf internal electrical connectionsof the electrical transmission device.

- Fig.v 7 isa diagram of electrical connections and circuits whereby the electrical transmission device unctions as a motor` to start the primemover, the ield rotor and -the inner armature rotor lbeing stationary and the other armature rotor turning.

.'Fig.'8 is a diagram of electrical connections and circuits whereb maximum torque for any given. speed of t e' prime mover is applied to...turn the driven member, all of the rotorsturning.-

9 is a diagram of electrical connections and circuitsl whereby regulation of the s eed of the driven member is obtained,

" all o the rotors turning.

Fig. l0 .is `a diagram of electrical connecytionsl and circuits whereby the' electrical transmission device may operate the driven member-at approximately .engine speed, all l of the rotors turning.

Fig. .l1 is a diagram of electrical connections and .circuits whereby when the engine is operating to drive the electricaltransmission device saidrdevice" may operate the driven member at greater speed than engine e engine is 'being driven by Asaid, device Isaid/engine will produce a braking effect, all ofthe rotors turning.

Fig. 12 is a diagram of electrical connections and circuits whereby the electrical 'transmission device may operate the driven member at greater speed than the engine speed and with greater power than the fengine power, all of the rotors turning except. inthe field rotor which is stationary. p

I ig. 13 is a diagram of electrical connecf tions and circuits whereby reverse driving of the driven member may be obtained withcurrent yfrom an external source, the field and vother armature rotors being stationary and the other rotor turning.

Fig. 15 is a diagram of electrical 'connections and circuits to permit of coasting, the

field rotor'I-being stationary andthe inner. v

rotorturning as generator and driving the ,outer rotoras motor.

Fig. 16 is a diagram of. electrical connections and circuits to permit of coasting, all of the rotors turning and the prime mover producing a braking effect.

Fig 17 is a diagram of electrical connections and circuits vwhereby the electrical transmission device functions as`a generator to charge the battery 1n mmimum time, the

eld rotor and inner armature rotor being vstationary and the other rotor turning.

. Fig. -18 is a'jdiagram of electrical co11`nec-v tions and circuits whereby compounding of the fields is e'ected to lessen the field strength, the M. M. F. of one field coil being opposed by the M. M. F. of the other field coil, and all of the rotors turning.

Fig. 19 is a diagram of electrical connec- -tions and circuits whereby Vcompounding of the 'field is effected to increase the field strength, the M. M.y F. of one ield coilbeing added to the M. M. Ff. ofthe other field coil,

and' all of the rotorsturning."

' Fig. 20 isa diagram of electrical'connections and circuits whereby forward rotation of the driven member is obtainedgwhen the field rotor is stationary and the other Arotors I are turning.

Fig. 21`is a plan View partly in section of a different form of the invention thanshown inFigs. 1 and 4, the wheels being omitted and portions of the frame being`broken away to contract the' view.

Fig. 22 is an enlarged fragmental sectionaldetail of the .field rotor.

There are provided concentricouter, intermediate and inner rotors l, 2, 3, the outer and inner rotors 1, 3y having suitable windings 4, 5 respectively 'and constituting rotative armatures and the intermediate -rotor 2 being provided, as clearl shown in Fig. 6, with main coils 6,4 7, supplbmental coils 8, 9 and commutating coils 10, 11, 12, 13, said intermediate rotor constituting a rotative eld, ',Ihe outer. and inner rotors l, 3 are 14, 15 respectively engaged by outer and inner brushes 16, 16 and 17, 17' respectively mounted in brush holders 18 which are connecte'd tol and are rotative with the field rotor 2. The winding of the armatures may be ofany suitable form and the invention is not limited to any1 particular form of' windfn the modifications shown in Figs. 1 and 4 the field rotor 2v'and inner armature rotor 3 are di'erent'iall connected to one another and in the modi cation shown in Fig. 21, the outer andk inner armature rotors are differentially connected to one another, and for this purpose said inner armature rotor is mounted on a shaft 19 provided with a year wheel 20 meshing with rgear wheels 21,

2 whichare -rotatively mounted on studs 23 projecting inward from and carried by a collar 24 that is pivotally connected by pins 25 and yoke 26 to va driven'member inthe formof a shaft/27, the gear wheels 20, 21,' .studs `23, 'ring 24, pins 25 and yoke 26, all

together formin' a universal joint for con necting the sha' 19to the shaft 27. 'The shaft 27 see Fig. 1, is connected by a uni` versal joint 28 to a shaft 29 having a gear 30 meshing 'with differential gearing 31 which is connected to axle sections 32 forming one of the axles of the'vehicle. Eachof 'the axle sections 32 is provided'with a traction wheel 33.

- The studs 23 arey rotatively mounted by 'anti-friction bearings 34 on the shaft 19 'and the gear wheels21, 22 mesh with a fourth gear wheeli3'5 which is rotatively mounted by an antifriction 'bearing 36 on the shaft 19.A The gear wheel 35 may be held against rotation when desired by a brake drum 37 which is provided'` with a brake band .38 and whichl may' be formed integral with l the gear 3.5 or connected thereto 1n any desired manner. The "brake band 38l may be contracted and expanded around the drum'37 by' any Asuitable .meansa not shown, such means being well known in the art. and therefore not necessary to show and describe in detail herein.

The gear wheel 35 and brake drum 37 are mounted on' a tubular shaft '39 surrounding the shaft 19 and concentric therewith, the forward en'd of said vtubular shaft being journaled by an anti-friction bearing 40 on the shaft 19 and being connected'to the field armature rotor 1 as in Fig. 21. The tubular shaft 39 is rotativelyv mounted externally by anti-friction bearings 41 ,i on atsuitable support such as, for instance, a vehicle frame or chassis 42. Y

From. the foregoing it is seen that the inner armature rotor f3 and the field rotor 2 or outer armature rotor 1,` as the case may be, mayturn at the same speed as one Van-v lrotor 2 as in Figs.' 1` and 4 or to the outer inner armature rotor and field rotor or outer armature rotor, as the case may be.

The `field rotor 2 is provided with any suit- Vable number of collector rings, there being shown in this instance twelve rings a, b, c, d, e, f, g, h, i, y', c, m which are rotative with the field.

The armature rotor .1 as in Figs. 1 and 4, and the field rotor 2 as in Fig. 21, are connected vto the shaft 43 of a prlme mover 44 such as a gas engine or the like, mounte on the vehicle f'rame42. rI he shaft 43 may be tubular as clearl shown in Fig. 2.

The foregoing the same for the forms of the linvention -shown in Figs. 1, 4 and 21 and the construction in the forms in Figs. 1 and 21 differentiating from that in A`ig. 4 will now be described. n

The shaftr 43, as shown in Fig. 2, surrounds and is concentric with a forward extension 45 of the armature shaft 19. The

yconnections between the shaft 19' and prime mover 44, in this instance, are constructed as follows: Each of the pitmen 46 of the prime mover is provided with a collar 47 working on an eccentricy 48 on the shaft 4 3, there being anti-friction bearings' 49 between the collars and eccentrics. Thus the prime mover 44 whenexerting power will drive the armature `rotor 1, as in Fig. 1 or will drive the field rotor 2 -as in Fig. 21, or, if the power is off, driving of the varmature rotor 1 or field. rotor, as the case maybe, will operate the prime mover.

The inner shaft 19, as shown clearly in Fig. 1, is connected by universal joints 50,

51 and a shaft 52 to va shaft 53 which is connected by a gear wheel 54 and `differential caring 55 to the vehicle front axle that is ormed by rotative intermediate sections 56 and non-rotative end sections 57. The intermediate axle sections 56 'are `connected by suitable gearing 58 to vehicle traction wheels 59 which are rotatively mounted at 60 on the axle end sections 57 From the nature of the views only one each of the end' sections 57, gearings 58 and bearingsA 60 are visible. The gearing 58 maybe of; any suitable construction capable of veffecting the driving of the wheels 59 and, in the instance shown in the drawings, said gearin isof the same construction as that disclose `in my co-pending application for patent for automobile'and therefore unnecessary to describe'in detaill herein.

From the foregoing it is seen that driving of the inner armature rotor 3 will cause rotation of the vehicle wheels .59 or, vice versahturningof the front wheels 59 will escribed construction is` the air gaps and in the` lof the armature core.

l 17 respectively and the brushes 16, 16, 17,

17 are electrically connected to the collector. rings a., b, i, j, respectively and the coils 6, 7 are electrically interconnected and the coils 7, 8 are electrically interconnected.

Some of the collector rings a to 7c inclusive and m may be variously interconnected and others may be variously yconnected in circuit with other electrical devices as will now be described.

The collector rings may either be `connected to or themselves constitute some of the terminals or contact members of a con- Atroller shown diagrammatically at 61 in Figs. 7 to 20 inclusive, said controller having other terminals or contact members fn., o, p, g, r, s, t, u, the ycontact Ymembers n, s being electrlcally connected to the terminals respectively of a rheostat 62 and the contact members t, lul being electrically connected to the terminals respectively of asecond rheostat 63 land the contact members o, 7' being` electrically connected to the respective ter- `95 minals of-a storage battery 64 and the contact members p, g being electrically con-y nected to the respective terminals of an underload circuit breaker 65.

The field coils 6, 8 surround a pole piece 66, the field coils 7, 9 surround a pole piece 67, the compensating coils 10, 12 surround a pole piece 68, and the compensating coils 11, 13 surround a pole piece 69. i

Owing to the fact that the coils 10, 11, 12, 13 need be comparatively small, the field coils 6, v7, 8, 9 may extend ,along a comparatively lgreat length of arc between the outer and inner rotors 1, 3 and consequently the pole pieces 66, 67 may also be extended along 110 a comparatively great length of arc. The advantage of this is that the area of the pole faces is maximized, thus minimizing the re-` quired M. M. 'F. of thefield and also minimizing the specific induction of the field in eripheral portion y minimizing the F., as is clear, the amount of copper requisite in the field coils is minimized as is also the space occupied by said coils.

The field coils 6, 7, 8, 9 and their pole pieces 66, 67 function for both armature rotors forproducing a 'resultant magnetic field. The advantage of this, as is evident,

is afurther saving in the requisite amount 125 Vte liti

`2 or outer armature rotor,

hysteresis in the armature cores and to eddy currents in the armature windings.

Another advantage of the magnetic iield being between the two concentric armatures is that thereby the amount of passive magnetic substance required for the magnetic iield isminimized, thereby minimizing the weight of and space occupied by the electrical device.

ylin some instancesthe M. M. F. of one armature winding compensates the M. M. F. of the other armature winding so as to minimize distortion of the magnetic field and enable. the use of air gaps of minimum size between `the field and acrmature rotors.

Operation of the prime mover 44 will drive the outer armature 1 as in Figs. Land 4 or will `drive the field rotor 2 as in Fig. 21 to generate current in said armature and the magnetic flux produced in said armature rotor will tend to rot'ate the lield rotor as the case may be, in the same direction as said armature rotor or field rotor, and the magnetic flux produced in said field rotor will tend to rotate the inner armature rotor 3. lt is clear that when all of the rotors are rotating at substantially like speeds the losses due to friction of the bearings, friction of the brushes`,`friction due to air resistance, waste lcurrent in coils `during commutation, hysteresis in armature cores, eddy currents in the armature cores and pole pieces and armature conductors, will be at a minimum and much less than when one or two of the rotors are stationary, and advantage is taken of this fact to obtain maximum speed and power when said losses are at minimum and to obtaini considerable braking eect when the electrical losses are greater than minimum.

lin Fig. l means are shown to produce braking eiiect on the inner armature 3, said means including vehicle brakes 70 on the wheels 33 and also including the driving connections between said wheels. and said armature rotor. 'lFhe braking eflfect from the brakes 70 is transmitted through the shaft 32 and gears 30, '31 to the shaft'27,v

thence to the housing 21, thence to theshait 39, thence to the field rotor 2.' Since the ro tation ofthe outer rotor 1 produces a magnetic flux in the rotor 2, lit is obvious that the magnetic linxproduced Ain the vrotor 2y has its eiiectupon the rotor 3 land slowing down or stopping of the rotor`2 will there- .'fzore cause braking action upon and conse- 4quent slowing down of the armature rotor -3.

ylin 'the torm of the invention in Figs. i and 4 the torque edect between theouter and intermediate rotors and between the intermediate and inner rotors is' in series, or

in other words, the relationsaresuch that slip occurs between the outer and intermediaterotors to ,thereby produce lag or, less 'netic iux to the electrical transmissiondevice.

retailer speed of the intermediate rotor than of the outer rotor and that slip also occurs between the intermediate and inner rotors to thereby produce lag or less speed 'of the inner rotor than of the intermediate rotor. i

the prime mover and yinner armature occurs only in one instance. From this it is clear that in Fig. 21 the innerl armature will rotate faster than in Figs. 1 and 4=at any given speed of the prime mover.

.ln practice, assuming at the start, for ex-f ample, that the prime mover 44 is stationary and the brakes 70, or the brake 37, 38, are on, if it be desired to start the prime mover, the controller 61 will be operated to close the contacts e, n and al, o, and c, p, and f, g, and s, r, as in Fig. 7 and the circuit breaker will be closed, whereupon electric current 'from the battery 64 willv 7 to produce mag-` turn the outer armature rotor 1 as motor, thereby driving the prime mover to start it into operation in a manner Well understood inthe gas engine art.

rlherotating armature produces a counter F. M. F .fand thereby operates the circuit breaker 65 to disconnect the battery frTom he magnetic flux of the coils 11 and 12 Jfunction to compensate portions of the magnetic tield and thereby 'prevent turning of the neutral plane of the resultant field and prevent sparking at the brushes.

After the prime mover is in operation, the vehicle brakes or the brake 37, 38, as the case may be, will be released and the controller 61 mayI be operated to close the contacts e n and b, f and a, s, and j, t and/u, z' as in Fig. 8 to -obtain high torque for starting the load. rFhe outer armature rotor l generates electric current `to energize the fieldv coils 6, 7 and thereby produce turning energize the ield coils 6,

drive the diderential gearwheel 20, the field rotor as in Figs. 1 and 4 or outer armature 'of the inner armature rotor 3 as motor` to.

rotor asin Fig. 21 also turning by reason of v the magnetic 'flux of the `oute'rarmature rotor. rFurning of the eld rotor 2, as in Figs.

4l and 4, or outer armature rotor 1 as in Fig.

21, operates the' gearv wheel 35. .'lhe rheostat 62is operated to' cut in more or less resistance toregulate the strength of the field and the. rheostat 63 is operated to oppose more or lessresistance to the electric current lilowing from the inner armature 3 in Y forml of the invention shown in Figsj1 andv .4,.the brake 37, 38 will be applied to hold proportion to the amount ofthe load on the device and other conditions such as the rade of. the surface on which the vehicle 1s running and :the character of said surface.

Differences in speedbetween the field and inner armature rotors as in Figs. 1' and 4 and between the inner and outer rotors as in Fig. 21, are compensatedby the differential gears-20, 21, 22, 35 which operate `to drive the shaft 27 torturn*l the rearwheels 33 as in Figs. 1 and 4 and to also turn the front wheels 59 as in Fig. 4.

Speed, regulation may be effected as in Fig. 9 by operating the controller 61 to close the contacts e, n, k and d, fland c, m,.u

and s, t to cause electric current generated 1n the outer armaturerotor 1 to flow through the field coils 6, 7 to produce niagnetic flux to turn the inner amature rotor 3. To produce the highest speed/(approximately engine speed) of the driven member 27, the rheostats 62, 63 will be operated to cutout all of their resistance, and, to slow down,

said rheostats will be operatedto cut inA more, and more resistance, thus effecting slower'and slower turning of the inner armature rotor 3. The slowing down of the armature rotor is due to the fact that the direction of current` in the innerarmaturerotor.y is such as to cause counter rotation of said inner armature rotor relative to the field rotor.' In consequence of this, tov ref` verse, the brake 37, 38 will be applied to hold the field "rotor as inv Figs. 1 and 4 or outer rotor 1 yas in Fig. 21 stationary7 and the inner armature rotor will than drive the shaft 27 backward.

Thevdriven member 27 may be driven at approximately engine s eed by also operating the controller 61 to c ose the contacts e d, n and b, f and a, j, u,` and s, t as in Fig. 10. o cause higher speed (approximately -engine speed) of the driven member 27, the rheo-V stats 62, 63 will be adjusted to cut out all of their resistance, and slowing down is accomplished by cutting in more andmore of said resistance at either or both of. the rheostats.

By entirely interrupting the shunt current at the rheostats 62, 63, the current may be reversed through the *inner armaturerotor 3 to drive the inner armature rotor counter Vto, the field rotor, thus slowing down said inner armature rotor. During this reversal the current will flow from the outer armature' rotor 14, throughthe brush.

16 to the contacts a, j, brush 17 inner rotor 15., brush 17, contactsl ,e, field coils 6, 47, brushes Inland brush 16 to the outer rotor. rom this it is clearthat, to reverse with the lcontacts closed as stated .for Vthe the field stationary` whereupon the inner armature rotor will drive the driven ymem-- ber backward instead of forward. In Fig. 2,1 the outer armature will be held statlonary.

.If it be desired to drive the driven member 27 at greater speed than the engine speed, the controller 61 will be adjusted to close the contacts a, e and b, j and f, z' as in Flg. 11. Themagne ic flux of the outer armature rotor 1 acts as turning power on the field rotor 2 as in Figs. 1 and 4 and on itself as in Fig. 21, and the magnetic 'flux of the field rotor acts as turning power on the inner armature rotor.

The current generated inthe outer armature not only energizes the field but also energlzes theinner armature winding 5 so as to produce electricalreaction between the inner armature rotor `andthe field rotor thus to drive said inner -armature rotor at ,al

mean of the speeds of the rotors 2, 3 is transmitted bythe gears 21, 2,2, 23, 35 to the shaft 27. d

When greater speed and power of ,the driven member 27 vis desired than can be produced by the prime mover, the brake 37 38 will* be set to hold the field rotor stationary as in Figs. 1 and 4 or outer rotor 1 stationary as in Fig. `21, and the controller 61 will be operated to close 'the contacts la, e .and b, n and '11, lc andy', o -and 7', s as in Fig. l12 so as to obtain the same effect as in F 1g. 11 with the addition,of increase of .pow'er'due to the E. M. F of the 'storage be operated to. close the contacts c, e and m,l n and d, lc and f, 8 as in Fig. 13, whereupon electric current generated in the outer arma ture rotor 1 will be supplied to the inneramature rotor 3 in reverse direction to that in Flg's. 7, 8, 10, 11, 12 to turn the inner varmature rotor counter vto the outer armature rotor. Reversal of the inner rotor 3 is also obtained as in Fig. 14 by setting the brake 37 38 to hold the field rotor stationaryand by operating the controller 61 to close the contacts e, n and k, 0 and f, m and `1', `a to energize the field coils "6, 7 and inner armature winding 5 by current 'from the battery 64, the inner varmature rotor operating as motor.

' f it be desired to obtainbraking action, the'brake 37 38 will be'set to hold the field rotor 2 lstationary as in Figs'. 1 and 4 orto hold'the outer armature rotoi` stationary as in Fig. 21, andthe controller 61 will be operated to close/the contacts e, n and, 1)8

vthe electrical transmission device.

rotor 1 as motor to drive the engine 4A against the resistance roduced by compression in the engine. hus braking action `of thefengine is obtained and further braking action 4is produced by the various losses in T de? crease the brake ed'ect of the losses in the device the brake 37, 38 will be released.

lin Fig. both armature windings d, 5 are in series with the field coils.

'llo obtain braking action. of less power l than with the brake setand connections in Fig. 15, the brake 37 ,'38 will be released' so as todiminish the brake eilect of the losses in thedevice, and the controller 61 will be operated to close the contacts-c, n`and7),gt

anda, u and f, j and t', s as in Fig. 16.

J ln Fig. 16 the inner armature winding 5 is in'series with the eld coils and rheostat 62,

and the outer armature Winding 'd is only in series with the rheostat 63, the advantage of this being a wide range of braking edect. When itis desired to recharge the battery 64, the brake37, 38 will be set to hold theeld rotor 2 stationary, as in Figs. 1 and A1 or to hold the outerarmature rotor 1 stationary as in'F ig. 21,` and the controller 61 will be operated to close the contacts @,e, o and. d, la, 11 and f,.s as "Fig, 17 to generate electric current in the outer armature rotor.

A very desirable way of regulating the `speed of the driven member 27 is shownin Fig. 18 and to obtain said regulation the controller 61 will be operated to close 'the contacts c, e and d, a and fm, t and sandgs 'and' 7L', u. rlhe signs of the M l.. F. of the.

tield coils 6, 7 are diderent from the signs of tlreM. M. F. of the field coils 8, 9 and conliti braio sum of the M. F.'oifthe eld co said algebraic sum being an arithmeticlifference. Theal-gebraic'sumof the M. M. Fs. is .increasedanddiminished by cutting out 'and in resistance at eitheror both of the rheostats 6 2, 63.

'Foobtain speed regulation in another, way, the controller 61 will be' operated to close the sequently the resultant1MfM--Fg is the algiecontactsde and k, t and m, g and al, n and fg 0,

s' and 7L, u asin Fig. 19, the algebraic sum the Fs. of the coils 6, 7, 8, 9 in this instance being an arithmetic sum.,` The alge-ve braicsumis increased and diminished as just described for Fig, 18.

. F rom the foregoing itis seen .that in Figs.

a, c, e and f, e and t, jand 1i, a as in Fig'. 20,

instaat thus reversing the direction of the current in the inner armature rotor to reverse said rotor and driven member27.

1t is noted that in Figs. 7, 17, 18 the compensating coils 10, 11 function to compensateportions of the magnetic field and thereby prevent turning of the neutral plane of the resultant lield to prevent sparking at the brushes and that-in Fig. 14 the compensating coils 12,13 function to prevent sparking at thebrush'es, and furthermore that in Figs. 9 13, 18, 19 the compensating coils'10, 11', 12, 13 all function` toprevent sparking at the brushesf ln relatively small aggregatesthe losses due to friction of the brushes-against the ycollector rings a, b, z", j, may be greater than 'the losses due to ohmic resistance inthe coils 10, 11, 12, 13 and consequently it may be advisableto lomit said collector rings and make suitable connections at the controller61 to 'cutin the boils 10, 11, 12,13 in series with the brushes 16, 16', 17, 17.', forinstance in rigs. e, 1o, 1r, 12,15', 1e, 2o the commute] will be v operated to cause tbecontacts lor rings c, d, It, m to be substituted for the contacts or rings 0 b, d and j. They coils 10, 11, 12, 13 may thus all be energized without distortingthe resultant magnetic eld for the reason that the. directionV of the current in a5 the coils 10, 11 is counter to that in lthe coils 12, 13 and therefore said coils nulliyy one another. t

. -lt is understood that the field coils 6, 7, v8, 9' may ybe compounded in Figs. 9, 10, 16 Aas in Figs. 18, 19 by 'making suitable connections at the controller as is readily understood by Ithe foregoing description inconnection with Figs.18, 19.

With the connections shown in Fig. 20, maximum available torque is produced, said torque being greater than the torque delivered by the engine shaft.

A As clearly shown inA Fig. 22, the held core is formed 'of spaced apart outwardly and invwardly expandin sections 71 which may be solid'or laminate as desired and which form between them relativelynarrow radial slots 72, 73 at the outer and inner margins ont the rotor. and relativel wider `,radial `slots '7d communicating with the slots 72, 73.? The tieldcoils may be disposed within some or' the slots 74 as inthedrawings, or if' desired 'said coils may be distributed in all ofsaid slots, as is readilyunderstood. v

Vlfhis construction otY the" eld core just .described is ot advantage to `reduce .eddy

current'losses in the Held rotor and also to -minimize armature'reactions in the resultant magnetic field.

y l claim.;

1. A primel mpver, concentric rotors having windings, one ot said rotors being connected 'to the prime mover, and a driven member connected to two other ot said lll@ ond one of said rotors, and means to drive a third one of said rotors, one of said rotors constituting a common field for the other rotors. y

4. Concentric outer and inner and intermediate rotors provided With windings respectively, differential gearing having one of,l its elements connected to lthe inner rotor and another` of its elements to the intermediate rotor, and means to drive the outer rotor, one of said rotors constituting a common field for the other rotors.

5. Concentric rotors provided with wind- ,ings respectively, dierential gearing havingl one of its elements connected to one of said rotors and having another of its elements connected to a second one of said rotors, breaking means for one of said differentially connected rotors, and'fmeans to drive a third one of said rotors.

6. Concentric outer and Vinner 'and intermediate rotors provided with windings` respectively, differential gearing havingone of its elements connected to the inner rotor and another of its elements to the intermediate rotor, braking means for the inter- :mediate rotor, and means to drive the outer rotor.

7 Concentric armatures, a pole piece intermediate ofV said armatures, and coils for said pole piece, means toA cause the sign of the M. M. F. of one of said coils` tobe different from the sign. of the M. M. F. of another of said coils to weaken the resultant 4magnetic field, said means being'operative of the M. M. F.\of saidy to cause the signs coils to be the sameI as onev another to strengthen the resultant magnetic-field, andmeans to increase and diminish the algebraic sum of the M. M. F. of the coils. j

8. Concentric armatures, pole pieces'intermediate of`-"sai.d armatures, a field coil forV one of' saidpole pieces, compensating coils for Yanother of saidpole pieces, and means to cause electric current to flow in one of saidcompensating coils counter to the electric current in another of said compensating coils soI that said compensating coils will nulli-lf3T one another.

9. Concentric armatures, pole pieces intermediate of said armatures, a field coil for one of said polepieces, compensating coils for another of said ole pieces, and means to cause the M. M. produced by the current in one of the compensating coils to compensate a portion of the field of one armature and to cause the M. vF. produced by the current in another of 'said compensating coils to compensate a portion of the field of the other armature.

10. Rotative outer and inner concentric rotative armatures, a field core rotatively mounted between said armatures, a coil for said field core, commutators for the armatures respectively, brushes rotative with the field core and engaging the commutatore respectively, and collector rings rotative withl said field core. l

11. Differential gearing, rotors having windings respectively, one of said rotors being connected to one element ofthe gear- ,ing and another of ,said rotors being con- -nected to a second element of-said gearing,

a `prime mover to 'drive a third one of said rotors, and a-driven member connected to a l third element of said'gearing.

' 12. A rotative armature, a field core concentric with said armatureY having a coil, a second rotative armature` concentric with the first armature and field core, and a controlleri adapted to connect 'the field .coil in series with the first .named armature and to connect the second armature in closed circuit` on itself.

.13. Aii armature, a field core concentric with said armature having la coil, a second armature concentric with thefirst armature,

and a'controller to connect the field coil in series with the first armature and to connect i the second armature iii series with the field` coil andrst armature.

14. An armature,l a field core concentric with s id armature havinga` coil, a second armature concentric with the first amature,

and to connect the rheostat in shunt with the armatures. f

15. An armature, a field core concentric with said armature havin a coil, a second armature concentric with t e first armature and field core, and a controller adapted to connect the field coil in series with the first larmature and to connect the second armature in seriesv with the first armature and field coil.

16. An armature, a field core concentric with said armature' having a coil, a rheostat, a second armature concentric with the first armature and field core, and a controller adapted to connect the field coil and rheostat and armature in series and to connect the positive pole of one armature to the negative pole of the other armature.

17. Concentric armatures, v for said field cores respectively, the sign of said field coils being different, a rheostat,

a rheostat, and a controller adapted to con--l Ineet the field coil and armatures in series field coi-es, coils tetonas coil designed to have its magnetic lines cut at one side by the armature Winding, other rotative Winding at the other side of the rotor to produce counter M. M. F., and means to produce relative movement between said armature and core.

lSigned at Los Angeles, California; this 7th day of Januaryl916. l

JACOB SCHURCH. Witnesses:

GEORGE H. HILES, ANNA- l?. SCHMIDTBAUER. 

